V3 partial idle

Subpage of Rev limit / Overrun / Safety dialog

Partial fuelcut idle control

  • With partially open throttle (ALS racecar) idleing and driving slowly is a pain.
  • Ignitioncut based idle pours a lot of exhaust through the engine, which has several problems:
    • fuel consumption
    • fuel can burn in exhaust (and exhaust can cause fire)
    • sparkplugs can be fouled
    • fuel can wash down into engine oil, degrading oil
    • possibly other
  • Fuelcut (individuel fueling events are skipped, with a pseudo-random algorithm, according to fueling demand) based power-control eliminates a lot of these. But care is needed, as always.
  • Configuration:
    • overrun_fuelcut - overrun_fuelresume = 10 that is 1000 RPM. If you don't want partial fuelcut, configure differently (like difference can be 900 or 1200 RPM)
    • example:
      • overrun_fuelcut=23 (3500 RPM)
      • overrun_fuelresume=19 (2500 RPM)
    • Which means
      • when TPS <= iac_tps_threshold, fuelcut grows from 0..100% while RPM grows 2500..3500 (above that full fuelcut, injpw=0)
      • TPS >= iac_tps_threshold + 25% no fuelcut at all (the +25% might change according to experience)
      • when TPS between these, partial fuelcut is still allowed accoring to TPS and RPM:
      • TPS pushes the 1000 RPM partial fuelcut window up by +4000 RPM / 24% TPS
    • partial fuelcut for TPS direction ONLY when rpmdiff is 1100rpm